#matheus sousa, exercicio 109.2

#instalando o pacote "plotrix"
install.packages("plotrix")
library(plotrix)

exp.analysis= function (x, y)
  {
  if(length(x)!=length(y))
    {
    stop("vectors \"x\" and \"y \" can't have different lenghts!")
    }
  x11()
  par(mfrow=c(3,2)) #setando dispositivo
  
  qqnorm(x,col="red",xlab="Theoretical Quantiles",ylab="Observed Quantiles", 
         main=" ",pch=16) #fazendo qqnorm do x
  qqline(x) #adicionando qqline de x
  qqnorm(y,col="blue",xlab="Theoretical Quantiles",ylab="Observed Quantiles",
         main= " ",pch=16) #fazendo qqnorm do y
  qqline(y) #adicionando qqline de y
  #plotando as densidades
  plot(density(x),xlab="X density distribuition",ylab="Density",type="l",main="",col="red")
  plot(density(y),xlab="Y density distribuition",ylab="Density",type="l",main="",col="blue")
  #boxplot
  boxplot(x,y,col=c("red","blue"),xname=FALSE,xaxt="n")
  axis(1,1:2,labels=c("X values","Y values"))
  #histogramas de frequecnia de valores de X e Y
  XY=list(x,y)
  multhist(XY,col=c("red","blue"),xlab="Values",ylab="Frequencies")
  cdx=c(0.5,2)
  cdy=c(0.5,1.95)
  legend(x=20.16309,y=4.127041,legend=c("X values","Y values"), 
         pch=c(16,16), 
         col=c("red","blue"),bty="n")
  #retornando aos parametros iniciais
  par(mfrow=c(1,1))
  summx=summary(x)
  summy=summary(y)
  cxy=cor(x, y)
  #finalizando e imprimindo resultados
  return(list(c("X characteristics:",summx),c("Y characteristics:",summy), c("Correlation coeficients between X and Y:",cxy)))
  
  }

